Refine course progression and runtime safety

s03_permission/code.py

@@ -8,13 +8,17 @@ Three gates inserted before tool execution:
     Gate 2: Rule matching (write outside workspace? destructive cmd?)
     Gate 3: User approval (pause and wait for confirmation)
 
-    +-------+    +--------+    +--------+    +--------+    +------+
-    | Tool  | -> | Gate 1 | -> | Gate 2 | -> | Gate 3 | -> | Exec |
-    | call  |    | deny?  |    | match? |    | allow? |    |      |
-    +-------+    +--------+    +--------+    +--------+    +------+
-         |            |             |             |
-         v            v             v             v
-      (normal)     (blocked)    (ask user)   (user says no?)
+    +----------+      +-------+      +--------------+      +---------------+
+    |   User   | ---> |  LLM  | ---> | Permission   | ---> | Tool Dispatch |
+    |  prompt  |      |       |      | 1. deny list |      | execute       |
+    +----------+      +---+---+      | 2. rules     |      +-------+-------+
+                          ^          | 3. approval  |              |
+                          |          +------+-------+              |
+                          |                 | deny                 |
+                          |                 v                      v
+                          |          +-------------------------------+
+                          +----------+ tool_result: denied or output |
+                                     +-------------------------------+
 
 Only one line added to the agent loop:
 
@@ -27,7 +31,8 @@ Builds on s02 (multi-tool). Usage:
     Needs: pip install anthropic python-dotenv + ANTHROPIC_API_KEY in .env
 """
 
-import os, subprocess
+import os
+import subprocess
 from pathlib import Path
 
 try:
@@ -53,9 +58,7 @@ MODEL = os.environ["MODEL_ID"]
 SYSTEM = f"You are a coding agent at {WORKDIR}. All destructive operations require user approval."
 
 
-# ═══════════════════════════════════════════════════════════
-#  FROM s02 : Tool Implementations
-# ═══════════════════════════════════════════════════════════
+# -- From s02: tool implementations --
 
 def run_bash(command: str) -> str:
     try:
@@ -111,9 +114,7 @@ def run_glob(pattern: str) -> str:
         return f"Error: {e}"
 
 
-# ═══════════════════════════════════════════════════════════
-#  FROM s02 (unchanged): Tool Definitions & Dispatch
-# ═══════════════════════════════════════════════════════════
+# -- From s02 (unchanged): tool definitions and dispatch --
 
 TOOLS = [
     {"name": "bash", "description": "Run a shell command.",
@@ -134,11 +135,9 @@ TOOL_HANDLERS = {
 }
 
 
-# ═══════════════════════════════════════════════════════════
-#  NEW in s03: Three-Gate Permission Pipeline
-# ═══════════════════════════════════════════════════════════
+# -- New in s03: three-gate permission pipeline --
 
-# Gate 1: Hard deny list — always forbidden
+# Gate 1: Hard deny list - always forbidden
 DENY_LIST = ["rm -rf /", "sudo", "shutdown", "reboot", "mkfs", "dd if=", "> /dev/sda"]
 
 def check_deny_list(command: str) -> str | None:
@@ -148,7 +147,7 @@ def check_deny_list(command: str) -> str | None:
     return None
 
 
-# Gate 2: Rule matching — context-dependent checks
+# Gate 2: Rule matching - context-dependent checks
 PERMISSION_RULES = [
     {"tools": ["read_file", "write_file", "edit_file"],
      "check": lambda args: not (WORKDIR / args.get("path", "")).resolve().is_relative_to(WORKDIR),
@@ -165,9 +164,9 @@ def check_rules(tool_name: str, args: dict) -> str | None:
     return None
 
 
-# Gate 3: User approval — wait for confirmation after rule match
+# Gate 3: User approval - wait for confirmation after rule match
 def ask_user(tool_name: str, args: dict, reason: str) -> str:
-    print(f"\n\033[33m⚠  {reason}\033[0m")
+    print(f"\n\033[33m[permission] {reason}\033[0m")
     print(f"   Tool: {tool_name}({args})")
     choice = input("   Allow? [y/N] ").strip().lower()
     return "allow" if choice in ("y", "yes") else "deny"
@@ -178,7 +177,7 @@ def check_permission(block) -> bool:
     if block.name == "bash":
         reason = check_deny_list(block.input.get("command", ""))
         if reason:
-            print(f"\n\033[31m⛔ {reason}\033[0m")
+            print(f"\n\033[31m[blocked] {reason}\033[0m")
             return False
     reason = check_rules(block.name, block.input)
     if reason:
@@ -188,9 +187,7 @@ def check_permission(block) -> bool:
     return True
 
 
-# ═══════════════════════════════════════════════════════════
-#  agent_loop — same as s02, with check_permission() inserted
-# ═══════════════════════════════════════════════════════════
+# -- Agent loop: same as s02, with check_permission() inserted --
 
 def agent_loop(messages: list):
     while True:
@@ -226,7 +223,7 @@ def agent_loop(messages: list):
 
 if __name__ == "__main__":
     print("s03: Permission")
-    print("输入问题，回车发送。输入 q 退出。\n")
+    print("Enter a question, press Enter to send. Type q to quit.\n")
 
     history = []
     while True: